1. Field of the invention
The present invention relates to an improvement of a self-developing camera, also called an instant camera.
2. Description of the prior art
In self-developing cameras for amateur use which use self-developing film, the camera body itself tends to be larger because their image frame size is larger than that of general miniature cameras. However, it would be advantageous that the camera body be smaller and of lighter weight and handles more easily. There have been many proposals relating to such self-developing cameras. For example, U.S. Pat. No. 3,709,122 discloses a self-developing camera that is a finder-collapsible compact single lens reflex camera. This camera has the disadvantage that because of the single lens reflex type, it needs to oscillate the reflex mirror each time when an exposure is made, so that the time lag between the time the shutter button is depressed and the time when an actual exposure is made is so long that an object can move during the time interval or an exposure is made with the mirror insufficiently settled, thus causing the resulting image to be degraded. In addition, because the collapsing of the finder is made by pivotting on 4 pivots, the mechanism is complicated. And if the angle formed by and between the sheet film plane and the reflex mirror plane is made less than 45.degree. and the space between the film plane and the mirror is small, the reflection is repeated many times between the film plane and the reflex mirror, tending to produce a ghost image. Further, if the self-developing camera has an exposure lens-foldaway structure wherein the lens is folded so as not to be superposed upon a film cassette when the camera is in the folded position because the image frame size thereof is relatively large, the camera body can be made flat, but instead its flat area becomes so large that its portability tends to be reduced.
Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 34530/1975 proposes a self-developing camera wherein an exposure lens member is pivotally coupled to an end of a film cassette holder, and also a reflex mirror is pivotally coupled to the other end of the holder, the two movable members being such as to be folded inwardly toward each other. In this camera, however, the exposure lens, as a barrier type, is difficult to fit inside the camera frame. In order to make the camera more compact, the exposure lens and reflex mirror are required to be located as close to each other as possible. If located too close to each other, the two become difficult to be folded inwardly toward each other, while if a sufficient space is provided between the two, the size of the camera in the picture-taking position becomes larger. In addition, the optical axis of the exposure lens, if brought closer to the film cassette holding position, produces a flare between the reflex mirror and the film plane, so that it may not be brought excessively close to the position. Accordingly, the proposed camera has the disadvantage that if the exposure lens and reflex mirror are to be folded inwardly toward each other with both ends of the holder as pivotal axes, the interval between both ends of the holder must be made larger, and the camera can be folded flat but tends to become so large that the portability thereof is reduced.